Recent concepts of water quality were applied for the evaluation of AI Qatif wells for irrigation. It was revealed that the ionic balance of this water tends to precipitate part of its calcium, causing a reduction of about 15 to 20% in the initial salinity to an equilibrated value of 2.4 to 3.5 mmhos/cm. This high salinity, high chloride water may cause severe reductions in the yield of sensitive crops. But satisfactory production of many tolerant crops might be more feasible by applying higher leaching fractions; improving the drainage efficiency of the whole area; and adopting management practices that inhibit salt accumulation in the soil column.